Great Pyramid of Giza

 The town of Necropolis borders Cairo in Africa. The Great Pyramid is The oldest and only remaining member of the Seven wonders of the world it is said that it took  over a 20 years to build and was completed around 2560BC. The Great Pyramid was built as a tomb for the Pharoa Khufu.  Which is why the pyramid is called Khufu's Pyramid sometimes.

The Great Pyramid of Giza is part of a complex of buildings that includes two mortuary temples in honor of Khufu (one close to the pyramid and one near the Nile), three small pyramids each of Khufu's wives, and an even smaller  pyramid, a raised causeway connecting the two temples, and small tombs surrounding the pyramid for the  nobles. One of the small pyramids contains the tomb of queen Het and thiswas discovered in 1925.She was the  sister and wife of Sneferu and the mother of Khufu. There was a town for the workers of Giza, including a cemetery, bakeries, a beer factory and a copper smelting complex. More buildings and complexes are being discovered by The Giza Mapping Project.

A few hundred metres south-west of the Great Pyramid lies a  smaller Pyramid called khafra, one of Khufu's successors who is also famously known as the builder of the Great Spinx , and a few hundred metres further south-west is the Pyramid of Menkaure, Khafre's successor, which is about half as tall.

The generally accepted estimated date of its completion is c. 2500 BC. Although this date contradicts some of the evidence provided by radiocarbon dating but it is loosely supported by a lack of archaeological findings for the existence prior to the fourth dynasty of a civilization with sufficient population or technical ability in the area.

Many varied estimates have been made regarding the workforce needed to construct the Great Pyramid. Herotus, the  historian in the 5th century BC, estimated that the construction may have required 100,000 workers for about  20 years. Recent evidence has been found that suggests the workforce was in fact paid  which would require accounting and bureaucratic skills of a high order. The Architect Wieslaw Kozinski believed that it took as many as 20 men to transport a 1.5-ton stone block. Based on this, he estimated the workforce to be 300,000 men on the construction site, with an additional 60,000 off-site. 19th century Egyptologist William Flinders Petrie  proposed that the workforce was largely composed not of slaves but of the rural Egyptian population, working during periods when the Nile  river was flooded and agricultural activity suspended. Egyptologist Miroslav Verner  posited that the labor was organized into a hierachy, consisting of two gangs of 100,000 men, divided into five zaa or phyle of 20,000 men each, which may have been further divided according to the skills of the workers.Some research suggests alternate estimates to the accepted workforce size. For instance, mathematician Kurt Mendosohn calculated that the workforce may have been 50,000 men at most, while Ludwig Borchartand Louis Croon placed the number at 36,000. According to Verner, a workforce of no more than 30,000 was needed in the Great Pyramid's construction.

A construction management study (testing) carried out by the firm Daniel ,Mann,Johnson & Mendenhall in association with Mark Lehner and other Egyptologists, estimates that the total project required an average workforce of 14,567 people and a peak workforce of 40,000. Without the use of pulleys, wheels, or iron tools, they surmise the Great Pyramid was completed from start to finish in approximately 10 years. Their critical path analysis  study reveals estimates that the number of blocks used in construction was between 2-2.8 million (an average of 2.4 million), but settles on a reduced finished total of 2 million after subtracting the estimated area of the hollow spaces of the chambers and galleries.Most sources agree on this number of blocks somewhere above 2.3 million. The Egyptologists' calculations suggest the workforce could have sustained a rate of 180 blocks per hour (3 blocks/minute) with ten hour work days for putting each individual block in place. They derived these estimates from construction projects that did not use modern machinery.